JavaScript Optional Chaining

The Problem

Accessing nested properties can cause errors:

```javascript const user = { address: null }; user.address.city; // Error! Cannot read property ```

The Solution: Optional Chaining

```javascript const user = { address: null }; user.address?.city; // undefined (no error!) ```

Usage

```javascript user?.name; user?.address?.city; user?.greet?.(); ```

Key Takeaway

Optional chaining (?.) safely accesses nested properties. Returns undefined instead of error. Essential for working with API data.